The talk will present a review and evaluation of monitoring methods that could be used for marine mammal monitoring for mitigation purposes in periods of low visibility during which the effectiveness of visual observers is reduced. Ursula will outline what low visibility monitoring methods are available and give an outline of their strengths and weaknesses to detect different species in different conditions:

Active acoustic monitoring, sound pulses are emitted into the water and acoustic reflections from an animal are received by hydrophones

Thermal IR (infrared imaging), uses an electro-optical imaging sensor to detect temperature differences between the body or the exhalation of the warm blooded marine mammal and that of the surrounding environment

RADAR, radio or micro-waves are emitted into the air and echoes from the animal’s body, its exhalation, or from disturbance on the sea surface are picked up by receivers